Combination accumulator and receiver



United States Patent C 3,212,289 COMBINATION ACCUMULATOR AND RECEIVER Edward W. Bottom, Brighton, Mich, assignor to Refrig.

eration Research Incorporated, Brighton, Mich, a corporation of Michigan Filed Feb. 12, 1963, Ser. No. 258,086 1 (Iiaim. (Cl. 62468) The present invention relates to a refrigeration component, and more particularly to an improved suction accumulator, the construction permitting the combination of the accumulator with a receiver in an integral unit to provide a desirable heat exchange relationship.

In copending application, Serial No. 169,771, now Patent No. 3,084,523, filed January 30, 1962, we have disclosed a refrigeration component combining a receiver, suction accumulator, mufller and heat exchanger in one integral unit. My present invention is a modification of the suction accumulator disclosed therein.

It is an object or" the invention to provide a suction accumulator which is particularly useful in systems which are operated intermittently such as heat pumps, air conditioning systems and other commercial refrigeration systems.

Another object of the invention is to provide a novel suction accumulator which acts to protect the compressor against undue shock resulting from the sudden injection of large amounts of liquid refrigerant, such shocks frequently resulting in broken valves, rods and the like.

A further object of the invention is to provide a suction accumulator comprising a casing With a conduit therein having a portion extending from a point adjacent the bottom of the casing to the casing outlet, the conduit having an opening in the portion adjacent the casing bottom and acting as a suction tube to draw liquid through the opening from the bottom of the casing and expel it into the casing outlet at a metered rate.

Another object of the invention is to provide a novel screening device for the opening in the conduit to prevent the opening from being clogged with foreign matter and to prevent the passage of foreign matter from the accumulator to the compressor.

A further object of the invention is to provide, in one embodiment, a combination of refrigeration components in one integral unit.

Another object of the invention is to provide a combination of components which result in a simplified structure of reduced cost, improved performance and increased efficiency.

A still further object is to provide, in one embodiment, an efiicient heat exchange between the cool refrigerant in the low pressure side and the warm refrigerant in the high pressure side of a given system.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corre sponding parts in the several views.

In the drawing:

FIGURE 1 is a side elevational view in section of one embodiment of the suction accumulator of the present invention;

FIGURE 2 is a sectional view taken substantially along the line 2-2 of FIGURE 1 looking in the direction of the arrows showing the screening device for the opening in the conduit within the suction accumulator; and

FIGURE 3 is a side elevational view in section of another embodiment of the refrigeration component of the present invention showing the combination of a receiver and suction accumulator in one integral unit.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

As shown in FIGURE 1, the suction accumulator 10 includes a casing 12 which comprises an open ended tube 14 having anupper end closure 16 and a lower end closure 1$ secured thereto.

An inlet tube 20 extends through the upper end closure 16. The tube 20 terminates in the upper portion of the casing 12. An outlet tube 22 is positioned adjacent the inlet tube 20 and also extends through the upper end closure 16. The inner end 24 of the tube 22 is of reduced diameter and receives one end of a U-tube 26. One leg 28 of the tube 26 extends from the outlet tube 22 downwardly to a point adjacent the lower end closure 18. The tube is then provided with a bend 30 and the second leg 32 extends upwardly and terminates in an open end 34 adjacent the upper end closure 16.

A small metering opening 36 is provided in the tube bend 30 A small tubular section 38 of larger diameter than the opening 36 is secured on the bend 30' over the opening 36. The tube section 38 has a circumferential flange 39 which is conformed to the contour of the tube 26 to form a saddle. The structure of the tube section 38 contributes measurably to the economy and practicality of assembling the device. In the assembly operation, the tube section 38 is placed on the tube bend 30 and centered over the opening 36. The tube 38 is then secured in place by spot welding the saddle to the tube 26. The accuracy of the placement of the tube 38 may be visually checked by looking therethrough. The saddle to tube 26 connection is then made fluid-tight by, for example, hydrogencopper brazing.

A sleeve-like screen 40 is received on the outer end of the tubular section 33. The screen may be fabricated from any desirable foraminous materials such as woven plastic or metal. As will be noted, the screen 40 has a generally cylindrical shape, with one open end 42 which is received on the tubular section 38. The other end 44 is closed as by seam welding. Consequently, any liquid or other material which passes through the tubular section 38 must first pass through the screen 40. The screen 40 thus acts to filter any foreign particles which may be present in the liquid refrigerant. The total area of the screen 40 is considerably larger than the area of the opening 36. The screen 40 is thus capable of collecting a relatively large amount of foreign matter. The amount of material which the screen 40 can collect before being clogged is much greater than the amount of material which would cause clogging of the opening 36. Additionally, during the process of the use of the accumulator, much of the material collected by the screen 49 will fall off the screen and settle in the bottom of the accumulator thereby virtually eliminating the problem of clogging in connection with the opening 36. Another advantage secured by use of the screen 40 is that the material which vflows from the accumulator to the compressor is free from foreign matter which might cause damage or clogging of the compressor.

In operation of the accumulator, cold refrigerant gas, having a small amount of entrained liquid refrigerant therein, normally enters through the tube 20 into the accumulator. The refrigerant gas is drawn into the open end 34 of the U-tube 26, passes through both legs of the U-tube and exits through the outlet tube 22 and thence to the compressor. The compressor, which creates a suction, draws the gaseous refrigerant through the accumulator at a relatively rapid rate.

If an unusual amount of liquid refrigerant enters the accumulator through the tube 20, it will drop to the bottom of the accumulator and will be subsequently drawn through the screen 40 and opening 36 and thence through the leg 28 into the compressor. The opening 36 acts as a restriction and causes the liquid refrigerant to be metered into the compressor at a controlled rate. The accumulator thus acts to prevent large amounts of liquid refrigerant and oil to suddenly enter the compressor. Such sudden surges of liquid often result in seriously damaging the compressor.

FIGURE 3 illustrates another embodiment of the invention. As will be noted, the accumulator is positioned within a receiver 46. The receiver 46 comprisses a casing 48 which includes an open ended tube 50 having an upper end closure 52 and a lower end closure 54 secured thereto. An externally threaded stud 56 is provided on the lower end closure 54 to facilitate mounting of the unit on a suitable support structure. A purge port 58 is provided in the upper end closure 52 to permit purging the receiver of air and non-condensable gases. The port 58 is normally closed by a threaded plug 60. A pressure release opening 62 is provided in the side wall of the tube 50. A fusible plug 64 is threadingly received in the opening 62 to normally seal the receiver. The plug 64 is hollow and has an interior wall member 66. The wall 66 will melt at a predetermined temperature and allow gas to escape to prevent explosion of the receiver. Instead of a fusible plug, a conventional pressure release valve may be used as desired.

A pair of openings 68, 70 are provided in the lower end of the tube 50 for the ingress and egress of refrigerant. These openings may however be located at any desired point on the casing. Externally threaded connector tubes 72, 74 are secured in the openings. In operation, the tube 72 may be connected to the condenser of a system and the tube 74 connected to the expansion valve, capillary, metering device, reversing valve or the like in which event high pressure liquid refrigerant would enter through the tube 72 and exit through the tube 74. However, the receiver may also be used in a reverse cycle system wherein the direction of flow is reversed.

Vertically spaced check ports 76, 78 are provided to serve as a liquid indicator, thereby eliminating the necessity for a sight glass. The ports 76, 78 are closed by threaded plugs 80, 82. The plugs 80, 82 maybe loosened to determine the level of the liquid in the receiver. In operation, the lower plug 80 may be first loosened, and if no liquid is ejected from the receiver, it is known that the level is below the plug 80. This level representing the desired level. If liquid does exit from the port 76 then this port is closed and the plug 82 loosened. If liquid exits from the port 78, then it is known that the liquid level is at an undesired high point.

A desiccant material 84 may be provided adjacent the bottom of the receiver. The desiccant is retained between annular screen 86, 88. A filler port 90, closed by a threaded plug 92, is provided to permit refilling of the desiccant material. This refilling feature permits the entire assembly, including the various tubes and closures to be permanently secured together to provide a unit which will not come apart in use. The various parts of the assembly are preferably fabricated from metal which may be hydrogen-copper brazed, this process being the preferred method of securing the component parts together to produce a unit of high quality and which requires a minimum of cleaning operation after the brazing process.

It will be noted that the inlet and outlet tubes 20, 22 of the accumulator 10 extend through the upper end closure 52 of the receiver 46 for attachment to suitable conduits. The operation of the accumulator 10 is substantially the same as described in connection with the PIG- URE l embodiment.

The arrangement of the accumulator and receiver in FIGURE 3 provides an efficient heat exchange between the relatively cold low-pressure refrigerant in the accumulator and the relatively warm high-pressure refrigerant in the receiver. The walls of the accumulator casing act as a heat exchanging medium. Such heat exchange is desirable for the efficient operation of a refrigeration system and in order to obtain full capacity.

Another important advantage residing in positioning the accumulator within the receiver casing is that the warm refrigerant in the receiver will prevent moisture in the atmosphere from condensing on the accumulator casing which contains cold refrigerant. When the accumulator is exposed directly to the atmosphere, there is a problem of dripping of moisture therefrom and a corrosion problem in connection with the accumulator casing.

The construction of the accumulator 10 may be varied within the scope of the invention. For example, rather than providing a U-tube within the accumulator, the accumulator may be constructed with inlet and outlet fittings and a small diameter tube which extends to the bottom of the accumulator and empties into the outlet fitting. Additionally, bafiies may be provided within the accumulator to act as mufilers to reduce the noise inherent in operation thereof.

Having thus described my invention, I claim:

A refrigeration component comprising a pair of casings one of which is positioned within the other, one of said casing defining a chamber to serve as a receiver, said receiver casing having an inlet and an outlet for refrigerant, said other casing being positioned entirely within the receiver casing defining a chamber having a top and bottom to serve as a suction accumulator for the compressor of a refrigeration system, said accumulator casing having an oulet positioned adjacent the top thereof and an inlet, a conduit within the accumulator casing having a portion with an opening extending from a point adjacent the bottom of the casing to the accumulator casing outlet, a tubular member extending from said opening, a sleeve of foraminous sheet material secured to the outer end of the tubular member, the outer end of the sleeve being closed, said sleeve having a greater area than the area of said opening, said conduit acting as a suction tube to draw liquid through said sleeve and tubular member from the bottom of the accumulator casing and expel it into the accumulator casing outlet at a metered rate.

References Cited by the Examiner UNITED STATES PATENTS 3,012,414 12/61 La Porte 62503 ROBERT A. OLEARY, Primary Examiner.

MEYER PERLIN, EDWARD J. MICHAEL, Examiners. 

